1. Field of the Invention
This invention relates to improvements in apparatus for directing oxygen into an effluent in a hydrocarbon secondary reforming process and more particularly, but not by way of limitation, to an apparatus having means for protection of the delivery equipment from the excessive heat created by the use of oxygen in a hydrocarbon secondary reforming process.
2. Description of the Prior Art
In the synthesis of ammonia it has been a practice to reform methane with steam to obtain hydrogen for combination with nitrogen to form anhydrous ammonia. This process has normally been carried out in apparatus referred to as a Primary Reformer, which adds heat to the mixture of steam and methane in the presence of a catalyst. The temperature level that may be attained in this type apparatus is limited and a large portion of the methane is not reacted. In order to obtain the reaction of a greater volume of the methane, it is considered necessary to utilize a Secondary Reformer in which the carbon monoxide, hydrogen and methane effluent or exhaust from the Primary Reformer is burned by the introduction of air to provide a temperature level of at least twenty-two hundred degrees Fahrenheit. At such temperatures the effluent from the Primary Reformer in the presence of the catalyst reacts with the residual methane to produce additional hydrogen and carbon monoxide. The hydrogen thus produced is combined with nitrogen for the production of anhydrous ammonia.
Secondary Reformer apparatus for achieving this increased efficiency is disclosed in the Reed U.S. Pat. No. 3,477,824, issued Nov. 11, 1969, and entitled "Burner and Apparatus for Reforming Hydrocarbons" and in the Reed et al U.S. Pat. No. 4,166,834, issued Sept. 4, 1979, and entitled "Air Injector Nozzle for Secondary Reformer." These devices generally comprise a housing or header having an inlet in communication with the exhaust or effluent from the Primary Reformer for receiving the effluent therefrom. The housing is secured to or in open communication with a reactor (or reaction vessel), or the like, containing a catalyst and wherein the secondary reforming process takes place. An air supply or air delivery pipe extends into and through the housing or header means and is provided with nozzle means, or the like, at the lower end thereof for injecting the air into the effluent flow stream at the proximity of the entry of the effluent into the reactor (or reaction vessel), or the like.
It has been discovered that the introduction of pure oxygen into the effluent in the secondary reformer process in lieu of the air stream greatly increases the efficiency of the secondary reformer operation. However the use of pure oxygen, or pure oxygen in combination with steam creates excessively high temperatures within the reactor (or reaction vessel), or the like, during the secondary reformer process. For example, the temperatures may reach three thousand degrees Fahrenheit in the reactor. One disadvantage of the use of oxygen in this process is that the excessively high temperatures are transmitted to the oxygen injector or delivery means and is destructive to the construction thereof. As a result, the useful life of the oxygen delivery means is relatively short, thus increasing the overall cost of the equipment and reducing the efficiency thereof.